The present invention relates to the general field of photonic crystals and, in particular, as photonic crystals relate to integrated circuits, optical interconnects and sensors.
Photonic crystals hold great promise for new and innovative micro- and nano-photonic and other light-emitting devices and is currently the subject of extensive research worldwide. For example, photonic crystals have the capability of revolutionizing the photonic industry, doing for light what silicon did for electrons. Complete photonic integrated circuits (PICs), including lasers, modulators, lossless bends and waveguides, etc., may be built monolithically on the same wafer by patterning the desired photonic crystal structure, just as integrated circuits and lasers are now fabricated. Such mass production and high yield fabrication of PICs will have a profound impact.
Current difficulties remain in the manufacturing and processing of photonic crystal structures, such as how to generate cost-effective photonic crystal structures with submicron features. While e-beam lithography is widely used, additional patterning methods that are as fast or faster and low cost, repeatable and reliable are required for generating high quality submicron sized photonic crystal structures. In addition, there remains a need to manufacture photonic crystal structures apart from the current follow-on microfabrication processes used to create metal contacts, etc. This is because air column lattice photonic crystals known in the art are mechanically and chemically susceptible to disruption, damage and/or degradation as a result of the exposed air columns on their top surface. Current practice is to complete all other fabrication processes before submicron feature patterning and photonic crystal structure formation. This approach, however, limits performance because it compromises the high quality submicron feature definition of the photonic crystal structure. In addition, the approach is not suitable for large area feature definition (e.g., PICs).
Accordingly, what is needed are improved manufacturing and processing methods of photonic crystal structures, particularly those that enable the creation of large area and high quality submicron features, those that protect the photonic crystal structure, its integrity and quality during processing and improve overall performance of the structure and device made there from.